davethomsen97

I'm in the process of building up a 5.3 for my 2003 silverado, it has a powerdyne supercharger on it which was installed new. My question is how far can the 5.3 be safely bored, from what i've read they can be bored out to 5.7 easy, so can they be bored safely to .010 over a 5.7, we want to be able to put forged pistons in. The Supercharger is staying on the truck, so any help would be great!

Sid447

You'd be better off picking up a 6.0litre block.

Same size and external dimensions.
Same weight too, I believe.

347fbody

texas speed has a 347 fully forged kit dat will work

SOMbitch

iTrader: (8)

The crank is the same just take it out to 3.905

slow67

iTrader: (2)

Wiseco now makes forged 5.3 pistons too

1FastBrick

iTrader: (16)

If you plan on using Forced Induction I would not recomend going .010 over the 5.7L spec. on a 5.3L Block. The reason is that the cylinder walls are at the very minimal thickness. By adding FI your just asking for trouble. An Iron 5.7L is not a bad thing but adding additional pressure and heat inside the cylinder is a recipe for disastser.

If your set on building an Iron 5.7L have the cylinder walls Sonic checked first. All though it's not overly common, A few guys on here have actually gone through the cylinder wall while boring out to the standard 5.7L Spec. I don't believe it is as much of a casting issue but more of a porosity issue from corrosion.

As mentioned you can now get forged slugs with a few differrent options from Wiseco for the 5.3 Blocks...

Good luck!!!